Today’s Question: I don’t understand why the various settings in Lightroom’s Catalog Settings dialog couldn’t just be put in the Preferences dialog. Is there some reason these options need to be separated?
Tim’s Quick Answer: There is actually a very important distinction between the Preferences and Catalog Settings dialogs in Lightroom Classic CC. The Preferences settings apply to the entirety of your Lightroom installation, while the Catalog Settings only relate to the catalog that is currently open. In other words, you can have different settings for each catalog in Lightroom through the Catalog Settings dialog.
More Detail: While I certainly can’t address the internal decision-making at Adobe as it relates to Lightroom, I can say that I very much appreciate that these two dialogs are separate, since there is a very important distinction between them.
As noted above, the settings in the Preferences dialog apply to the local Lightroom installation. That means that no matter which catalog you open, the settings in Preferences will apply equally.
By contrast, the settings found in the Catalog Settings dialog only apply to the current catalog. It is therefore possible to have different settings for different catalogs, if you use more than one catalog in your workflow.
Of course, this also means you could create an issue where you change the settings for one catalog in the Catalog Settings dialog, but then don’t make the same changes for any other catalogs you’re using.
So, any changes made in the Preferences dialog will apply universally to your Lightroom installation. Changes made in the Catalog Settings dialog will only affect the current catalog, so you will need to open each of your catalogs and update the settings if you want those changes to apply to more than just the current catalog.